Lewis Hamilton edged home hero Fernando Alonso in final practice for Sunday's Italian Grand Prix by the slenderest of margins.

Just one thousandth of a second separated Hamilton in his McLaren and current championship leader Alonso for Ferrari after 5.793km of the Monza circuit.

Hamilton, currently firmly in the spotlight regarding his future, managed to improve on the best time he set from Friday by 0.7secs.

The 27-year-old, determined to focus on his racing this weekend but distracted by talk as to whether he will remain at McLaren or jump ship to Mercedes, posted a lap of one minute 24.578secs.

With Alonso in as close attendance as possibly could be, the duo were comfortably clear of Force India's Paul Di Resta, surprisingly third quickest.

The Scot will need to match that position in qualifying to give himself any chance of a strong points finish tomorrow given he has a five-place grid penalty for an unscheduled gearbox change.

Di Resta finished 0.271 secs behind Hamilton and was followed by Felipe Massa in his Ferrari, the Brazilian looking strong for once, and the second McLaren of Jenson Button, 0.416secs down.

The places from sixth to 10th were filled by five different marques courtesy of Nico Rosberg for Mercedes, Sauber's Sergio Perez, the Lotus of Kimi Raikkonen, Force India's Nico Hulkenberg and Williams' Pastor Maldonado.

Noticeably, there was no Red Bull in the top 10, with Mark Webber 11th and Sebastian Vettel 12th, the latter causing concern late on when he pulled over his car as it lost power, claiming over the team radio he had "no battery".

Overall, the top 14 were remarkably covered by under a second, with Bruno Senna in his Williams and Michael Schumacher for Mercedes 13th and 14th, the latter 0.985secs adrift.

Jerome D'Ambrosio, standing in for the banned Romain Grosjean this weekend after the Frenchman caused a first corner pile-up in last Sunday's Belgian Grand Prix, was a disappointing 17th and 1.395secs back.

Bringing up the rear were again the HRT pair, but this time with Narain Karthikeyan ahead of Pedro de la Rosa, the latter 3.8secs off the pace.